Process for producing low sulphur and high cetane number petroleum fuel

ABSTRACT

A process is disclosed for producing low sulfur and high Cetane Number petroleum fuel, the process comprises providing fuel, adding acid source, aluminum, base source, heating the mixture, separating fuel from water, and adding at least one additive in order to raise the Cetane Number.

DESCRIPTION OF THE RELATED ART

The present invention relates to a process for reducing Sulphur content in petroleum fuel, such as diesel, and raising the Cetane Number higher than 50.

Cetane Number is an indication of the ignition quality of a diesel fuel. It is a relative measure of the interval between the beginning of injection and auto ignition of the fuel. This is the time period between the start of injection and start of combustion (ignition) of the fuel. The higher the number, the shorter the delay interval.

Low Cetane Numbers will likely cause hard starting, rough operation, noise and exhaust smoke. Generally, diesel engines will operate better on fuels with Cetane Numbers above 50 compared to fuels with Cetane Numbers of U.S. national average of approximately 45.

It is also desirable to have a low Sulfur content. Sulfur is directly related to corrosion in engines.

Those skilled in the art have long sought producing fuel with higher Cetane Number and low Sulfur content. For example, Salazar, U.S. Pat. No. 5,770,047 to Salazar, et al., discloses a process for producing reformulated gasoline by reducing sulfur, nitrogen and olefin. The process includes conatcting fuel with a catalytically metalic active matrix inclduing two metals, a support medium distributed through the matrix having a silicious molecular sieve, mixing the fuel with acid. The process is done under hydrogen temperature and pressure.

However, Salazar does not disclose use of aluminum and additives to raise Cetane Number. Salazar's process is also complicated because it requires use of specially designed catalytic matrix.

Mead, U.S. Pat. No. 4,088,566 discloses a process for producing low sulfur petroleum fuel. The process comprises contacting the fuel with oxygen-containing gas, mixing the fuel with acid and neutralizing the acid with base. The process requires high temperature of about 400 degrees to 675 degree Fahrenheit. However, the process requires high temperatures.

Schmidt, U.S. Pat. No. 4,806,232, discloses a process for reducing sulfur content of fuel. The process includes the steps of adding metal to the fuel and heating the fuel mixture without oxygen at a temperature of about 500 degrees C. Schmidt's process, however, requires high temperature and pressure.

One particular disadvantage with the prior art is that the processes require especially designed matrixes and high operation temperature and pressure.

Another disadvantage is these refining processes are complicated and expensive.

OBJECTS OF THE INVENTION

It is an object of this invention to provide for a simple and inexpensive process for reducing sulfur content and raising Cetane Number.

An additional object of the invention is to provide for a process for reducing sulphur and raising Cetane Number of a petroleum fuel at an atmospheric pressure and low temperature.

An additional object of the invention is to provide for a process for reducing sulphur content of petroleum fuel by mixing fuel with aluminium.

A still further object of the invention is to provide for a process for reducing sulphur content of petroleum fuel by at least 50%.

It is still another object of the invention to provide for a process for raising Cetane Number of petroleum fuel using simple additives such as methanol.

SUMMARY OF THE INVENTION

The above-listed objects are met or exceeded by the present invention. The present invention discloses a process for desulfurizing petroleum fuel and raising Cetane Number comprising providing petroleum fuel; adding at least one acid source to said fuel, preferably oxidizing said acid; adding aluminium to said fuel; heating the mixture to about preferably between 80 to 100 degrees C.; adding at least one base source, water, sodium, bicarbonate at a temperature range preferably about 100 to 120 degrees C.; separating fuel form water, and adding at least one additive to raise the Cetane Number such as alcohol and preferably methanol, alkyl esters of inorganic acids and preferably alkyl nitrate, peroxides and combinations thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to a process for producing low sulphur and high Cetane Number petroleum fuel. The process includes preferably two phases. The first phase includes receiving petroleum fuel to be treated. The fuel temperature is preferably 80 to 100 degrees C. The fuel is then mixed with an acid source, preferably sulphuric acid or any other acid. The process may be done in the presence of oxygen. The fuel is mixed with a metal and preferably aluminium and preferably in solid state. The pressure could be an atmospheric pressure. This phase may take an average of about between 8 to 12 hours depending on the level of sulphur in the fuel and the quantity of fuel being treated.

In the second phase, the fuel is mixed with a base source, such as sodium hydroxide or any other basic compound, and/ or salt, such as sodium bicarbonate, in order to neutralize the acid. The fuel should be heated to a temperature of preferably about 100 to 120 degrees C. The fuel should be mixed well. The process can be performed at an atmospheric pressure. This phase may take about 3 to 4 hours. The resulting fuel is sent to a separator where fuel naturally separates from water.

An additional step is also used to raise the Cetane Number. At least one additive is added to the fuel. The at least one additive is preferably an alcohol, such as methanol, alkyl esters of inorganic acids, such as alkyl nitrate, butyl nitrate, amyl nitrate, isobutyl nitrate, and the likes, and peroxides, and combinations thereof.

The present process reduces sulphur content by about at least 50% and raises the Cetane Number higher than 50. The present process is simple and inexpensive treatment of petroleum fuel to improve its ignition quality and provide cleaner fuel.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the scope and spirit thereof. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as those within the scope of the appended claims. 

1. A process for producing low sulphur and high cetane number petroleum fuel, said process comprising the steps of: providing a petroleum fuel; adding an acid source to said fuel; adding aluminum to said fuel; adding a base source to neutralize said acid source; and heating said fuel.
 2. The process as set forth in claim 1 wherein said fuel having a temperature range of about 80 to 100 degrees C.
 3. The process as set forth in claim 1 further comprising the step of adding sodium carbonate and water to said fuel after step D.
 4. The process as set forth in claim 1 wherein step E includes heating said fuel to about 100 to 120 degrees C.
 5. The process as set forth in claim 1 further comprising the step of separating said fuel from water.
 6. The process as set forth in claim 5 further comprising the step of adding at least one additive to said fuel to raise the Cetane Number.
 7. The process as set forth in claim 6 wherein said at least one additive is an alcohol.
 8. The process as set forth in claim 7 wherein said alcohol is methanol.
 9. The process as set forth in claim 6 wherein said at least one additive is an alkyl ester of inorganic acids.
 10. The process as set forth in claim 9 wherein said alky ester is an alkyl nitrate.
 11. A process for producing low sulphur and high Cetane Number petroleum fuel comprising: providing petroleum fuel; adding at least one acid source to said fuel; adding aluminium to said fuel; and adding at least one base source to said fuel.
 12. The process as set forth in claim 11 further including oxidizing said acid source.
 13. The process as set forth in claim 11 further including heating said fuel.
 14. The process as set forth in claim 11 further including adding water and sodium bicarbonate to said fuel.
 15. The process as set forth in claim 11 further including separating fuel from water.
 16. The process as set forth in claim 11 further including heating said fuel.
 17. The process as set forth in claim 11 further including adding at least one additive to raise the Cetane Number.
 18. A process for producing petroleum fuel having low sulphur content and having a Cetane Number greater than 50, said process comprising the steps of: providing petroleum fuel; providing at least one acid source; adding aluminium to said fuel; adding at least one base source to said fuel; and adding at least one additive to said fuel.
 19. The process as set forth in claim 18 wherein said fuel having a temperature of between 80 to 100 degrees C.
 20. The process as set forth in claim 18 further including the step of adding water and salt after step D.
 21. The process as set forth in claim 18 further including the step of separating water from said fuel before step E.
 22. The process as set forth in claim 18 further including the step of heating said fuel to a temperature range of between 100 to 120 degrees C. after step C.
 23. The process as set forth in claim 18 wherein said at least one additive comprises, alcohol, alkyl esters of inorganic acids, peroxides, and combinations thereof. 